The invention relates to an arrangement for fastening a hydraulic clutch operating device, particularly a clutch operating cylinder.
For fastening such clutch operating devices, it is generally known to provide a fastening flange laterally at the end of the cylinder. The fastening flange is used to fasten the clutch operating cylinder, by means of fastening screws, on a casing of the internal-combustion engine or of the transmission. The installation or removal of this highly stressed component is often difficult because an easy access to the fastening screws is often difficult to achieve.
German Patent Document DE-AS 17 50 532 discloses a hydrostatic clutch operating device in which the operating cylinder is suspended between the clutch release lever and a ball pin screwed into the engine block. The clutch operating cylinder is not guided or secured in the radial direction.
It is therefore an object of the invention to improve the fastening of a clutch operating cylinder such that it can be mounted or demounted in a simple manner in the transmission case of an internal-combustion engine, while, when installed, it is simultaneously fastened such that it can securely transmit the operating forces absorbed by it to the clutch release mechanism.
How this object is achieved is described as follows. The arrangement according to the invention and the clutch operating cylinder according to the invention each include a simple construction which permits a one-handed mounting of the clutch operating cylinder into the transmission case. Only one fastening screw is used to fasten the clutch operating cylinder on the casing which protects it from being lost. In this case, among other things, because of a pressure spring arranged in the clutch operating cylinder, a self-holding mounting position is achieved. While it is conventional to use, for example, two fastening screws to fasten the open end of the cylinder, through which the push rod is guided on the casing of the internal-combustion engine, only a radial guiding is provided within an opening in the transmission case in the present invention. Because the other end of the operating cylinder is axially supported on the transmission case, the fastening screw provided at this end is free of operating forces and is therefore used only for securing the operating cylinder on the transmission case of the internal-combustion engine.
Additional advantageous developments and improvements of the arrangement according to the invention and of the clutch operating cylinder according to the invention are described as follows.
An elastic sleeve, which closes off the open end of the operating cylinder and surrounds the push rod, is fastened on a flange part of the operating cylinder so that, when installed, the section of the sleeve placed over the flange rests on its exterior side against the interior wall of the transmission case opening. This advantageously achieves a play-free radial accommodation of the clutch operating cylinder in the transmission case.
Because the ring section of the sleeve is toroidally curved toward the outside, the clutch operating cylinder can be introduced by means of its sleeve slide in a simple manner diagonally into the opening of the transmission case in order to be changed or swivelled by means of its rearward end into the fastening position. It is only in this position that the maximal contact surface is achieved between the interior wall of the transmission case opening and the toroidal ring section of the sleeve, which contact surface ensures a secure radial guidance of the clutch operating cylinder.
The radial recesses provided on the interior side of the ring section of the sleeve advantageously increase the radial elasticity of the sleeve arranged between the interior wall of the transmission case opening and the clutch operating casing.
Because of a ring-type sealing lip provided on the sleeve, dirty water, or similar substances, cannot enter the clutch space by way of the transmission case opening. In addition, as a result of the spring effect of the ring-type sealing lip supported axially on an exterior surface of the transmission case opening, a self-holding end position of the clutch operating cylinder is achieved.
Because of a stop provided at the cylinder end, the clutch operating cylinder can in a simple manner be clamped into a projection of the transmission case.